The Maxwell bridge as a circuit element in electromagnetic feedback seismographs

1968 ◽  
Vol 58 (5) ◽  
pp. 1621-1630
Author(s):  
R. D. Russell ◽  
R. D. Meldrum ◽  
O. G. Jensen
Keyword(s):  
Mechanical Properties ◽  
Effective Mass ◽  
Negative Feedback ◽  
Dynamic Range ◽  
Continuous Operation ◽  
Signal To Noise ◽  
Circuit Element ◽  
Mass Spring ◽  
Principal Advantage ◽  
Impedance Bridge

Abstract The characteristics of a seismograph can be modified by the use of filters or by the application of negative feedback. Both methods provide the same basic signal to noise capabilities, and each has its particular advantages. The principal advantage of the feedback instrument is its flexibility and the possibility of linearity over a greater dynamic range. The application of electrical feedback to a seismometer requires the creation of normally nonexistent electrical input terminals. By incorporating the seismometer into a balanced Maxwell impedance bridge, input terminals can be simulated and the feedback introduced through the bridge. With the use of such negative feedback, it is possible to control individually the effective mass, spring and damping constants of a seismometer. One instrument can thereby simulate seismometers of very different mechanical properties. For example, it is possible to increase the effective mass of a Willmore Mark I seismometer to well over one ton. A feedback seismograph has been constructed using these principles and has been in continuous operation for nearly two years.

An Over 120dB Dynamic Range Linear Response Single Exposure CMOS Image Sensor with Two-stage Lateral Overflow Integration Trench Capacitors

2020 ◽  
Vol 2020 (7) ◽  
pp. 143-1-143-6 ◽  
Author(s):  
Yasuyuki Fujihara ◽  
Maasa Murata ◽  
Shota Nakayama ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Linear Response ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Signal To Noise ◽  
Single Exposure ◽  
Two Stage ◽  
Noise Ratio ◽  
Maximum Signal

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.

scholarly journals Modeling Pulsed High-Power Spikes to Drive Piezoelectric Broadband Transducers Improving SNR in Ultrasonic Imaging & NDE

2021 ◽  
Author(s):  
Antonio Ramos ◽  
Abelardo Ruiz ◽  
Enrique Riera
Keyword(s):  
High Power ◽  
Dynamic Range ◽  
Ultrasonic Imaging ◽  
Average Power ◽  
Pulsed Power ◽  
Moderate Intensity ◽  
Signal To Noise ◽  
Discharge Generator ◽  
Piezoelectric Devices ◽  
Very High

Ultrasonic imaging & NDE applications can greatly improve their signal-to-noise ratios (SNR) by driving each transducer (composing piezoelectric arrays) with a spike giving pulsed power of k-Watts, repetitively at a PRF = 5000 spikes/s, by using a HV capacitive-discharge generator. However very-high levels, of pulsed intensities (3-10 A) and voltages (300-700 V) must be considered for a rigorous spike modeling. Even though the consumed "average" power will be small, the intensity through each transducer achieves several amperes, so the pulsed powers delivered by each HV generator can attain levels higher than in CW high-power ultrasonic applications: e.g., up to 5 kW / spike. This is concluded here from a transient modeling of the loaded generator. Then, unforeseen phenomena rise: intense brief pulses of driving power & emitted force in transducers, and non-linearities in driver semiconductors, because their characteristic curves only include linear ranges. But fortunately, piezoelectric devices working in this intense regime do not show serious heating problems, because the average power remains being moderate. Intensity, power and voltage, driving a broadband transducer from a HV capacitive pulser, are calculated to drastically improve (in ≅ 40 dB) the ultrasonic net dynamic range available, with emitted forces ≅ 250 Newtons pp and E/R received pulses of 70 V pp.

BANDWIDTH OF THE RECEIVER OF DIGITAL SIGNALS WITH A LARGE DYNAMIC RANGE

2021 ◽  
Vol 0 (11) ◽  
Author(s):  
A. E. Denisov ◽  
◽  
D. P. Danilaev ◽  
G. I. Il'in ◽  
◽  
...  
Keyword(s):  
Communication Channel ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Digital Signals ◽  
Resolution Time ◽  
Large Dynamic Range ◽  
Signal To Noise ◽  
Radio Engineering ◽  
Channel Parameters ◽  
Analytical Relations

The analysis of the connection between the bandwidth and the dynamic range, the signal-to-noise ratio, the resolution time and the bandwidth is carried out. The problems are solved by deriving analytical dependencies based on the Shannon – Hartley theorem, as well as the well-known postulates of the theory of radio engineering circuits and signals. The study of analytical relations allows us to identify restrictions on the choice of communication channel parameters.

Fabric Simulation Using Measurement Data for Dress Design

2014 ◽  
Author(s):  
Ayumi Hara ◽  
Hideki Aoyama ◽  
Tetsuo Oya
Keyword(s):  
Mechanical Properties ◽  
Evaluation System ◽  
Contact Point ◽  
Measurement Data ◽  
Previous Method ◽  
The State ◽  
Design Element ◽  
Simple Mass ◽  
Mass Spring ◽  
Fashion Designers

The state of wrinkles and folds formed on our dress according to human postures and movements is an important design element. Fashion designers must envisage the fabric state as wrinkling and folding. However, this is not easy because the fabric state strongly depends on the mechanical properties of the fabric, and in this sense, fabric simulation can aid designers in envisaging the fabric state. In previous works on fabric simulation, fabric models are proposed and developed based on the simple mass spring model. Since none of the models proposed so far take into account the state of slipping at the contact point of the warp and weft, simulated results differ from real fabric states. This paper proposes a method to simulate real fabric state taking into consideration slipping. In order to obtain real simulation results, the mechanical properties of fabric obtained by KES: Kawabata Evaluation System [1], were used in the simulation. The effectiveness of the proposed model was confirmed by comparing simulated results obtained by the proposed method with simulated results obtained by a previous method. In addition, it was verified by comparing the simulated results obtained by the proposed method with real cloth states.

A 20-MHz BW MASH Sigma–Delta Modulator with Mismatch Noise Randomization for Multi-Bit DACs

2019 ◽  
Vol 29 (07) ◽  
pp. 2050108
Author(s):  
Di Li ◽  
Chunlong Fei ◽  
Qidong Zhang ◽  
Yani Li ◽  
Yintang Yang
Keyword(s):  
Dynamic Range ◽  
Sampling Rate ◽  
Oxide Semiconductor ◽  
Quantization Noise ◽  
Cmos Process ◽  
Noise Shaping ◽  
Signal To Noise ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Chip Area

A high-linearity Multi-stAge noise SHaping (MASH) 2–2–2 sigma–delta modulator (SDM) for 20-MHz signal bandwidth (BW) was presented. Multi-bit quantizers were employed in each stage to provide a sufficiently low quantization noise level and thus improve the signal-to-noise ratio (SNR) performance of the modulator. Mismatch noise in the internal multi-bit digital-to-analog converters (DACs) was analyzed in detail, and an alternative randomization scheme based on multi-layer butterfly-type network was proposed to suppress spurious tones in the output spectrum. Fabricated in a 0.18-[Formula: see text]m single–poly 4-metal Complementary Metal Oxide Semiconductor (CMOS) process, the modulator occupied a chip area of 0.45[Formula: see text]mm2, and dissipated a power of 28.8[Formula: see text]mW from a 1.8-V power supply at a sampling rate of 320[Formula: see text]MHz. The measured spurious-free dynamic range (SFDR) was 94[Formula: see text]dB where 17-dB improvement was achieved by applying the randomizers for multi-bit DACs in the first two stages. The peak signal-to-noise and distortion ratio (SNDR) was 76.9[Formula: see text]dB at [Formula: see text]1 dBFS @ 2.5-MHz input, and the figure-of-merit (FOM) was 126[Formula: see text]pJ/conv.

A ΣΔ MODULATOR USING GAIN-BOOST CLASS-C INVERTER FOR AUDIO APPLICATIONS

2013 ◽  
Vol 22 (10) ◽  
pp. 1340024
Author(s):  
HAO LUO ◽  
YAN HAN ◽  
RAY C. C. CHEUNG ◽  
TIANLIN CAO ◽  
XIAOPENG LIU ◽  
...  
Keyword(s):  
High Resolution ◽  
Dynamic Range ◽  
Supply Voltage ◽  
Cmos Process ◽  
Signal To Noise ◽  
Dc Gain ◽  
Micro Power ◽  
Class C ◽  
On Chip ◽  
Σδ Modulator

This paper provides an audio 2-1 cascaded ΣΔ modulator using a novel gain-boost class-C inverter. The gain-boost class-C inverter behaves as a subthreshold amplifier. By introducing a gain-boost module, the inverter DC-gain is increased from 48 dB to 67 dB. The gain-boost class-C inverter consumes 57 μW at 1.2-V supply, where the gain-boost module consumes only 3 μW. In addition, an on-chip body bias technique is introduced to compensate the process and supply voltage variations of the class-C inverter. The proposed inverter-based ΣΔ modulator chip is implemented in 0.13-μm CMOS process, and achieves 86-dB peak-signal to noise and distortion ratio (SNDR) and 90-dB dynamic range (DR) over 22.05-KHz bandwidth at 1.2-V supply consuming 360 μW, which demonstrates that the gain-boost class-C inverter is particularly suitable for micro-power high-resolution applications.

The tunable electronic structure and mechanical properties of halogenated silicene: a first-principles study

2015 ◽  
Vol 3 (13) ◽  
pp. 3087-3094 ◽  
Author(s):  
Wei-Bing Zhang ◽  
Zhi-Bo Song ◽  
Liu-Ming Dou
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
Effective Mass ◽  
Elastic Properties ◽  
First Principles ◽  
First Principles Study ◽  
Carrier Effective Mass ◽  
Enhanced Stability

Halogenated silicene, with enhanced stability compared with silicene, presents a moderate and tunable direct gap with small carrier effective mass and improved elastic properties.

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